9. Review of fisheries management of small water bodies in Africa, Asia and Latin
America

This chapter provides an overview of inland fisheries, with special emphasis on small
water bodies, in seven selected countries of Africa, Asia, and Latin America. These
countries, Zimbabwe, India, Thailand, Sri Lanka, Brazil, Cuba and Mexico, have developing
economies and a growing national awareness of the importance of environment-friendly fish
production from inland water bodies as common denominators. It has been widely recognized
that the significance of freshwater catches to food security in developing countries
cannot be assessed by production figures alone. Their relevance to food security is
related to the overriding presence of subsistence and marginal fishers in the system and
the tendency toward local consumption of the products. The three Asian countries, India,
Thailand and Sri Lanka, have a high population density compared to their counterparts in
Africa and Latin America (Table 9.1). Nonetheless, all of them have a low per caput income
and insufficient nutritional standards; therefore, the fish yield optimization from small
inland water bodies is considered an important developmental activity.

Table 9.1

Location, area and population density of
the countries studied

Country

Latitude

Longitude

Area

Population Density

(km2)

(inhabitants/km2

)

Zimbabwe

15°35'-22°30'N

25°10'-35°05'E

391 000

28

India

08°04'-37°06'N

67°7'-97°25'E

3 287 728

273

Thailand

005°40'-20°30'N

97°20'-105°45'E

523 115

109

Sri Lanka

05°-09°80'N

79°84'-82°E

65 000

246

Brazil

7°33'N-33°45'S

34°47'-73° 59'W

8 511 965

19

Cuba

19°49'-23°17'N

74°08'-84°57'W

110 860

94

Mexico

14°-33° N

86°-117°W

1 958 201

46

The small water bodies gain special importance in the developing world because of their
unmistakable role in promoting fisheries development through mass participation of the
local population. Traditionally, these water bodies have been used as common property
resources (CPRs) where unrestricted access is allowed to inhabitants of the surrounding
communities. However, owing to a recent increase in population, the sustainability of
these small water bodies is questionable. The growing trend of converting them into
intensive aquaculture systems is to be viewed with caution because of the impacts on the
environment and the socio-economic problems created. Intensive aquaculture is essentially
a capital-intensive activity undertaken by corporate houses or industrialists aiming to
make a quick profit, and the profit generated is often shared by a few. Unless the local
people are provided with alternative employment, large-scale unemployment leading to
social dislocation could develop.

Many developing countries have realized that it is wiser to encourage culture-based
fisheries or extensive aquaculture in their inland water bodies which are more compatible
to the traditional practice of sharing nature's wealth among many, even if it means that
less income is generated. Although unrestricted open access to water bodies is no longer
feasible, mass participation can still be achieved through participatory management,
cooperatives and other such institutions. Any community aiming for social justice has to
reduce social tension emerging from skewed distribution of wealth generated in the
commodity sector.

9.1 Small water bodies

"Small water body" is a loosely used term covering natural and artificial
water bodies such as reservoirs, lakes, ponds, floodplain lakes and rivers. Although all
these different types of SWBs are present in varying proportions in most of the countries,
the man-made impoundments are invariably the main constituent. The preeminent position of
reservoirs among the SWBs is attributable to the greater magnitude of the resource size
and the national prioritization of fishery development in the countries. Consequently, a
major share of the reliable data on the inventory, fisheries management, species
management and other related aspects in the countries is confined to the reservoirs. Even
if such data exist on other resources, they are scattered and inaccessible; therefore,
this report has a circumstantial bias in favour of small reservoirs.

9.1.1 Distribution of small water bodies other than reservoirs

In many countries natural lakes are either rare or remotely placed and often there is
no separate management plan for their fisheries. Traditional artisanal fisheries prevalent
in the countries reviewed are not stripped of their subsistence character, thereby making
it difficult to make considerable commitments, in terms of human resources and finance, in
order to maintain authentic records for planning purposes. Mexico has a substantial number
of natural lakes of volcanic and tectonic origin, which are limnologically distinct from
their man-made counterparts. Some of them, such as Lake Yuriria in Guanajuato State, are
natural lakes modified by man. A chief characteristic of natural lakes is the low rate of
water renewal which results in weed choking. Many of these lakes have dangerously low
water levels and are well on their way to swampification and reclamation. The problems are
further aggravated by man-induced eutrophication. SEMARNAP does not seem to have made any
distinction between natural and man-made lakes with regard to their fisheries management
norms. Many natural lakes such as Patzcuaro have been stocked with a number of exotic fish
which have established superiority over the native species.

While ponds are an important resource in some of the countries such as India and
Brazil, where intensive aquaculture is growing in popularity, other small water bodies
play a minor role in terms of production in all the countries. India has the widest
spectrum of small water bodies other than reservoirs. Rivers, canals, floodplain lakes and
ponds of the country hold promising potential for fishery development, although the extent
of their contribution to total inland fish production is not precisely known. Aside from
having one of the largest water surface areas of ponds, the country has extensive deltaic
stretches of two major river systems of the subcontinent fanning into networks of oxbow
lakes. The floodplain wetlands and the estuarine impoundments are important inland fishery
resources in India. In small countries such as Zimbabwe, Cuba and Sri Lanka, production
contributions from water bodies other than reservoirs are negligible (Table 9.2). Details
regarding resource size and the fishery potential of swamps, floodplains and small river
systems of Brazil and Mexico are not available.

Table 9.2

The major inland fisheries resources of
the countries

Country

Small reservoirs

Rivers

Floodplain lakes

Ponds

Number

Area

(ha)

(km)

(ha)

(ha)

Zimbabwe

10 747

117 662

5 700

-

40

India

19 134

1 485 557

29 000

202 213

2 200 000

Sri Lanka

10 000

39 271

-

-

-

Thailand

1 745

425 500

12 000

4 049

16 330

Brazil

18 280

997 000

-

-

400 000

Cuba

2 228

124 000

3 932

-

-

Mexico

1 589

194 486

-

-

30 077

9.1.2 Distribution of reservoirs

The prevailing geoclimatic features of a country have a bearing on the number and
distribution of man-made impoundments. Undulated land provides an ideal setting for the
construction of hydroelectric projects. India, Zimbabwe, Brazil and Mexico have tall
mountain ranges bordered by plains into which rivers disperse providing ideal sites for
the creation of reservoirs.

Brazil has utilized the hydroelectric potentials of the great Amazon, Parana, Sao
Francisco and other large river systems, meeting more than 90% of the country's power
requirements. In the Indian subcontinent, the river systems originating in the Himalayas,
Vindhyas, Satpuras, and the Western Ghats provide many ideal sites on which to build large
dams for the generation of hydroelectric power, irrigation and the exploitation of fishery
wealth. Sri Lanka and Cuba have numerous smaller rivers that radiate down in all
directions from the central highlands. Traditionally, these small rivers were utilized for
small irrigation projects and as a result there are many such small water bodies in these
island countries contributing significantly to fish production. While in Cuba, these
artificial small water bodies are of recent origin, Sri Lanka has inherited one of the
world's oldest networks of irrigation reservoirs from its ancient rulers.

Uneven distribution of rainfall makes the creation of storage reservoirs essential for
supporting agriculture and animal husbandry. Some communities have developed traditional
skills, dating back thousands of years, in making irrigation reservoirs. In India,
Thailand, Zimbabwe, Sri Lanka and Brazil, there are great variations in the distribution
of rainfall, and marked divisions exist between wet and arid regions within each country.
In the arid and semi-arid areas, local inhabitants have been creating small impoundments
for their crops and animals since ancient times. Many Sri Lankan reservoirs can be traced
back 2 000 years.

In India, 90% of the monsoon rainfall and the ensuing surface flow take place during a
very brief span of two to three months, thus irrigation reservoirs are essential for
survival, especially in the Deccan plateau where more than 16500 small and mostly ancient
irrigation reservoirs exist. A similar preponderance of small man-made water bodies can be
seen in the northeastern semi-arid area of Thailand, northeastern Brazil, a major portion
of Sri Lanka and the northern states of Mexico.

9.2 Factors determining fisheries development of small water
bodies

The factors determining fisheries development in small water bodies can be broadly
classified under the following headings:

resource size (number and area of water bodies);

management systems;

stock enhancement; and

national priorities.

9.2.1 Resource size

The number and surface area of reservoirs are constantly increasing in the countries
under review. The three large countries, Brazil, India and Mexico, have the highest number
and surface area of reservoirs. However, the smaller countries have much larger areas of
man-made impoundments in relation to their size. Sri Lanka has more than 10000 reservoirs
covering 149762 ha of surface area within its total geographic area of 65000 km2,
i.e. 230 ha of reservoirs for every 100 km2, the highest density of reservoir
area for any country in the world. A high density of small reservoirs can be observed in
the three states of south India, Andhra Pradesh, Karnataka and Tamil Nadu, situated within
the Deccan plateau. Cuba has the highest density of small reservoirs (111 ha/km2),
followed by Sri Lanka (88 ha/km2), Thailand (81 ha/km2), and India
(45 ha/km2), as shown in Table 9.3.

Table 9.3

Reservoir fishery resources of the seven
countries

Country

Reservoir area

Reservoir density

(ha)

(ha/100 km2)

Small

Total

Small

Total

Zimbabwe

117 662

545 236

3

139

India

1 485 557

3 153 366

45

95

Thailand

425 500

718 090

81

137

Sri Lanka

39 271

149 762

88

230

Brazil

997 000

4 920 000

12

58

Cuba

123 577

148 000

111

133

Mexico

194 486

1 132 974

10

58

9.2.2 Management systems

There are marked variations in the fishery management practices followed for different
water bodies such as reservoirs, ponds, floodplains and rivers. The heavy bias in favour
of reservoirs is mainly attributable to the higher priority they received at the national
level and the greater availability of information on them. Ponds were second in order of
priority. In all countries the fishing activities employed on rivers and floodplains are
at the traditional, artisanal level, and practically no information is available on them.
Even though the reservoirs are owned by the government or corporate agencies in most of
the countries, fishing rights and exploitation systems vary from country to country. The
fishing systems fall under the following broad categories:

privately owned and managed reservoirs;

public water bodies;

community water bodies; and

water bodies owned and managed by the government.

Privately owned reservoirs

Privately owned reservoirs are very rare in many developing countries. Possible
exceptions are the small impoundments created by rich private farmers in Zimbabwe to
irrigate the large agricultural farms and for cattle ranching. However, they add very
little to the total fish production of the country. More than 90% of the fish production
in Zimbabwe is attributable to the catch from the Kariba reservoir. Privately owned
reservoirs are also present in Brazil for irrigating sugarcane fields and for aquaculture.

Public water bodies

Many reservoirs fall under the category of public water bodies made and maintained by
the government or public sector organizations for power generation or irrigation purposes.
In these reservoirs fishery is invariably a secondary activity, governed directly by the
agencies which created the lake or the respective fisheries departments. In Brazil, power
and irrigation companies manage the fisheries directly, while in Mexico and India, though
the lakes are owned by other agencies, the fisheries are managed by the fisheries
departments of the respective states in India and the SEMARNAP in Mexico.

Licensing:

In a typical situation, the government fixes the number of fishers,
their quota of fishing nets and the mesh size. The fishers obtain a licence from the
government for a fee and are bound by the stipulations regarding closed season, minimum
capture size and other conservation measures. The government, in turn, stocks the
reservoir with the required number and species of fish and provides infrastructure,
transport and marketing support. Sometimes financial assistance in the form of subsidies
and loans is extended to the fishers. Among the countries, Zimbabwe has the most stringent
restrictions on fishing. Using gillnets in rivers is categorically prohibited and a
licence is required for manufacturing, storing, buying or selling them. Fishing gear which
is detrimental to the fish populations is banned.

The licences are issued by the local officers of the state or central fisheries
departments in most of the countries. They make their own arbitrary assessment of the
maximum fishing effort the reservoir can accommodate. Zimbabwe and Mexico have protracted
procedures for issuing licenses involving a number of agencies

Indian states such as Andhra Pradesh do not levy license fees on the fishers. In
Zimbabwe and Mexico, there are national agencies (AGRITEX and SEMARNAP) that strive to
coordinate and implement a uniform national policy to manage such water bodies. A similar
attempt was made in Thailand in the form of Village Fish Pond Project.

A common feature of all the public water bodies in the countries is the significant
presence of intermediaries, mostly unauthorized, who finance the fishers and market their
catch. The intermediaries advance money on easy terms without requiring a guarantee or
collateral and, in turn, collect the fishers' catches at low prices. As the number of
market intermediaries increases, the fishers' share of the price decreases. The lengths of
market chains are determined by the remoteness of the reservoir, the proximity to the
market and, above all, the level of awareness of the fishers of their rights.
Well-organized and well-informed fishers protect themselves from exploitation by
undertaking marketing functions. Many governments have made earnest attempts to free the
fishers from the clutches of intermediaries by encouraging cooperative societies, but this
has had limited success.

In recent years, many state governments in India have created public sector fisheries
corporations which manage some of the reservoirs. The smaller reservoirs are managed by
local governments at district, taluk (an administrative division below the
district level) or village levels.

Crop sharing:

In some of the Indian states, a system of crop sharing is followed,
whereby the fishers give a share of their catch to the government as royalty. The royalty
varies from 25 to 50%, depending on the productivity of the reservoir. In the crop sharing
system, the government supplies boats, nets and all other fishing implements.

Leasing

: Leasing of reservoirs to private individuals for fishing is a common
practice in India, especially in the States of Karnataka, Uttar Pradesh and Rajasthan.
Only a few of the small reservoirs are leased out by auction to the highest bidders for a
period of one to two years. The state fisheries department, the district administration
and the village administration reserve the right to auction depending on the size of the
water body.

Community water bodies

Community water bodies are found mostly in Zimbabwe, northeastern Thailand,
northeastern Brazil and some parts of Mexico. The common property norm and open access
policy of these loosely organized fishery systems often play a negative role in
management. In Zimbabwe, one-fourth of the total number of reservoirs and 34% of the their
surface area are community reservoirs. Many community reservoirs are legacies of the past
and their fishery practices are deeply entwined with the customs and traditional values of
the local community. For example, in Zimbabwe the fishers have open access to all local
and adjacent community reservoirs. Normally, the local village chief selects the fishers
or issues permission to them. Enforcement of conservation norms and fishing effort
restrictions are intricate tasks.

In the community reservoirs of northeastern Thailand, fish population management norms,
including those concerning mesh regulations, minimum fish size and fishing effort, are
overlooked in order to honour the local custom. The situation in northeastern Brazil is
similar. In the reservoirs on the ejido land of Mexico, the water, and by
implication the fish caught from it, belong to the whole community. The ejido is
administered by elected officials, who often flout SEMARNAP regulations.

Recent efforts made in Zimbabwe (the Mwange experiment) and Brazil (Caxitore) to
develop a new participatory management system are worth examining. The basic aim is to
blend the concept of equitable sharing of natural resources with that of conservation and
sustainable development, while seeking to encourage the spirit of equity and democracy in
the members of the community.

State controlled management

Cuba is the only country of those studied where reservoir fishery management is totally
state controlled. A noteworthy feature of Cuba's fishing system is the national
homogeneity of the exploitation system. All fishing boats and gear, accessories, and the
entire infrastructure are owned by the state. The fishers receive wages and the fish
caught from the reservoir is fed into the national network of the public distribution
system. Since all the nets are imported and supplied to the fishers by the government,
there is very little scope for an increase in fishing effort and the use of destructive
mesh sizes as observed in the more democratic societies. Since all types of fish are sold
at the same price in Cuba, there is no exploitation of any particular species. This
regimented and unitary system is conducive to sound fishery management.

There is a well-organized network of fish seed production centres in Cuba, which caters
almost exclusively to the stocking requirements of reservoirs. In the other countries, the
unlimited demand for fish seed of the well-developed and growing aquaculture industry
absorbs most of the fish seed.

However, state management has its own shortcomings, the most significant being the lack
of motivation on the part of the fishers to maximize their catch. State-run marketing
leaves little room for entrepreneurship and often acts as a disincentive for production.

The marketing channels in all countries follow more or less a common pattern with a
number of intermediaries involved in the marketing process, resulting in poor price
realization for the fishers. Cuba, where a free market is yet to be developed, is the
exception. In India, market intervention attempts made in the past by a number of
fisheries corporations in state governments have not shown the desired result.

The common property norm

Management practices adopted in the different countries are characterized by an
underlying spirit of the common property norm, with the possible exception of Zimbabwe
where more than one-half of the reservoirs are privately owned. In Cuba, the scope of the
common property norm has been further widened to include depositing the catches from
reservoirs into a common national pool. In many reservoirs of Zimbabwe, northeastern
Brazil, northeastern Thailand and the ejidos of Mexico, age-old community
management is still operational along with the licensing system used in the other
reservoirs. The majority of Indian and Sri Lankan reservoirs are public properties where a
fixed number of licensed fishers make their living. An exception is found in India where
the small reservoirs in some states such as Karnataka and Uttar Pradesh are auctioned to
private individuals on an annual basis. Thus, the common property norm is a consistent
feature of the reservoirs under review. Despite this, the management strategy has to be
country-specific taking local conditions into account.

Management practices followed in the countries are summarized as follows:

Zimbabwe

: Most of the reservoirs are under private or community ownership. A
licensing system with state control on fishing effort and introductions is being
developed. The fishing restrictions are among the most stringent in the world. Cooperative
societies are not organized.

India

: Most of the reservoirs are public water bodies under licensing systems.
Crop sharing and auction systems are also present. Water bodies are owned by irrigation
and power generation departments of the state governments, but the right for fisheries
management remains with the state fisheries departments. Fishers are organized into
cooperative societies which are not always very effective.

Thailand

: Large reservoirs are state-owned and used by licensed fishers.
Fisheries of small reservoirs are not well organized. The traditional practice of
community fishing is followed in small reservoirs of the northeast.

Sri Lanka

: Reservoirs are considered public water bodies as far as fishing
rights are concerned. A licensing system is followed. Cooperative societies are organized
but not very effective.

Brazil

: Fisheries of large water bodies are managed by public sector
companies. Fishing licences are issued by these companies through cooperatives. Small
water bodies of the northeast are managed on a community basis.

Cuba

: The government owns and manages all water bodies and hires the fishers.
Catches go to a national pool for distribution through a public distribution system.

Mexico

: Large water bodies are owned by the government. Fishing is controlled
by a licensing system. Cooperatives are being organized. Small reservoirs in some areas
are still under community management.

9.2.3 Fishery management

Fishery management based purely on capture as in the case of marine fisheries seldom
operates in inland waters as most of the lakes and reservoirs in the world are managed on
the basis of culture-based fisheries. There is a general consensus that any significant
improvement in yield from the inland waters in future can be achieved only through
enhancement measures. These measures involve human intervention in the aquatic ecosystems
with a view to increasing their productivity. Aside from improving the production of
absolute biomass from the water bodies, access to the fisheries or their monetary and
aesthetic value could be developed. The common modes of enhancement followed in inland
water bodies are: increasing the stock (stock enhancement); introducing new species to
broaden the catch structure (species enhancement); and, improving the water quality
through artificial eutrophication (environmental enhancement).

Enhancement offers delicate management options to be exercised with care, especially
where the water bodies contiguous with natural ecosystems are involved. This can trigger
complex, intricate and often subtle changes in the habitats and biotic communities. The
nature and extent of the enhancement will determine the overall sustainabilty and
environment-friendliness of the fishery.

Stock enhancement

Augmenting the stock of fish has been the most commonly followed management measure in
the reservoirs in most of the countries in the world. Ever since the reservoirs were
considered a fishery resource it has become apparent that the original fish stock of the
parent river is insufficient to support a fishery. Augmentation of the stock was also
necessary to prevent unwanted fish from utilizing the available food niches, hence
flourishing at the cost of economically important species. All of the seven countries
under study have undertaken programmes to stock their water bodies, especially reservoirs,
but the stocking rate and selection of species have not always been very systematic.
Policies and guidelines on the subject are often erratic and even arbitrary. Aside from
the absence of any existing standards, the general lack of understanding of production
processes and the scarce availability of facilities prevent effective stocking.

Fish seed production has made rapid progress in the countries under study during the
last few decades either through indigenous or imported technologies. Consequently, a
number of hatcheries for mass-scale production of fish seed have emerged under the public
and private sectors. India has registered phenomenal growth in fish seed production during
the last few decades. After a technological breakthrough in induced carp breeding in the
1970s, a country-wide network of fish seed farms was set up under the government
departments to produce Indian and exotic carp fry and fingerlings. During the 1980s and
1990s the private sector dominated the scene. However, despite a remarkable increase in
carp seed production, the open water bodies of the country remain understocked as all the
seed produced in the private sector goes to the privately managed aquaculture industry.
The government hatcheries responsible for stocking the public reservoirs could not produce
the required number and species of fingerlings. A similar situation prevails in Mexico.

Cuba has adequately stocked its reservoirs through a well-organized fish seed
production subsystem. More than 70% of the seed produced in the 26 aquaculture centres of
the country is used for stocking the reservoirs. Sri Lanka has only two seed production
centres stocking the reservoirs of the entire country. These centres were taken over by
the private sector in 1990 when state support for inland fisheries was withdrawn. The
restocking programme of Zimbabwe, which focuses mainly on the natural seed of tilapia
collected from the reservoirs, was taken up under FAO's Special Relief Operation Programme
to repopulate the reservoirs that dried up during the devastating droughts of 1991-92. The
Village Fish Pond Project of Thailand procures fish seed from private fish farmers.

Stocking strategies

: Stocking measures undertaken by most of the countries lacked
specific strategies or a sound biological basis. Large countries such as India, Mexico and
Brazil with many water bodies had inadequate state support to meet all the stocking
requirements which resulted in understocking of the reservoirs. Since some seed species
were always in short supply owing to breeding difficulties, there was a common tendency to
stock the seed that was readily available, particularly in India and Thailand. In India
common carp is stocked in large numbers just to meet the stocking target. The Village
Fisheries Project of Thailand places emphasis on the quantity of seed stocked rather than
the species in evaluating performance.

In Sri Lanka, the high yield rate is attributable to the naturalized populations of
tilapia; therefore, stocking had limited impact on a short-term basis. However, periodic
stocking is important in order to renew the genetic vigour of the stock and to correct the
imbalances that arise from overfishing. Restrictions on stocking of exotic fish imposed by
the authorities of India and Brazil need careful examination. In India, the introduction
of exotic carp, especially the silver carp and Nile tilapia, into the reservoirs is not
encouraged. For the last three decades, the Indian reservoirs have been stocked with
catla, rohu and mrigal which failed to make an impact on any of the large peninsular
reservoirs primarily because of their failure to breed. While the stocking and recapture
method may suit the extensive aquaculture of small reservoirs, it has limited use in the
larger ones. The huge amount spent on stocking large reservoirs over the years has been
found to be of no avail. As all attempts to establish naturalized populations of Indian
major carp have failed in the large reservoirs, exotic species like O. niloticus
need to be tried.

The Sri Lankan experience shows that the Nile tilapia can establish themselves in the
reservoirs and support sustained fishery. Gangetic carp are alien to the peninsular
drainages and have already affected a number of cyprinids in the south Indian rivers.
Considering that the 3million ha of reservoirs in India produce on average 20 kg/ha, the
production loss owing to the lack of suitable species cannot be overlooked in a country
where fish yield optimization from inland fisheries is considered a priority area.

The stocking policy of large reservoirs in Brazil also has some inconsistencies. The
IBAMA stipulation of breeding and stocking only local species will not necessarily lead to
the recovery of the species affected by dam construction. The loss of some species because
of habitat changes is to be taken into consideration as continued stocking of such fish
may not yield any tangible results. The conservation of species can be better achieved in
India and Brazil by earmarking some designated areas as sanctuaries, while the development
potential of fisheries in the remaining areas needs to be exploited to the maximum extent.

Species enhancement

Species richness:

The spatial heterogeneity of a country has a direct bearing on
the richness of its species. The fish species diversity of the seven countries varied,
depending on the number of river systems present and the varying zoogeographic
affiliations of the species they harbour. India and Brazil have a wide spectrum of
habitats and a correspondingly high fish species diversity. Various river systems of India
are reported to harbour more than 400 species of fish, more than one-half of which are
indigenous to the Ganga system. Brazil, with mighty rivers such as the Amazon and Parana,
has a wide spectrum of fish species. Zimbabwe has 122 native fish species, which is not
very impressive considering that 3000 species of freshwater fish exist in Africa. The two
island nations, Sri Lanka and Cuba, have very few indigenous fish species because of poor
habitat diversity and early separation from their respective mainlands. There are only 36
native fish species in the rivers of Cuba and 25 in the rivers of Sri Lanka. Thailand,
with its major rivers and its connection with the Mekong river system, has a high species
diversity. Mexico has a good representation of the neotropical species. Decline of
indigenous fish stocks owing to habitat loss, especially that caused by dam construction,
is a universal phenomenon. The extent of loss of such fish species is not assessed to any
reliable degree in many countries. In India, all the major river basins have been
affected.

Introduction of exotics

The policy option of introducing exotic fish into a country to augment the fisheries is
implemented mainly on the basis of a national assessment of indigenous fish species and
their yield optimization (Table 9.4). The three main objectives for introductions made to
date have been to control insects, ornamental purposes, and to augment recreational
fishing and food fisheries. The ornamental fish remain more or less confined to the
aquarium tanks and the insecticidal value of fish is still uncertain. It is the
introduction of the fish species for food and recreational value that often provokes more
animated debate from an environmental point of view. The introductions can be
distinguished as:

introduction for intensive aquaculture; and

introduction for extensive aquaculture in reservoirs.

Introduction of fish for exclusive use in culture systems is considered harmless
according to the national views held in many countries. This is based on the premise that
the fish remain confined to the ponds and do not affect the natural fauna. The national
policy of Brazil makes a clear distinction between using alien species for intensive
aquaculture and stocking them in reservoirs. In India, despite the ambivalence regarding
the policy, there is an also an underlying distinction between the two uses of alien
species. After the initial stocking spree in the 1950s and 1960s, tilapia is no longer
stocked in the southern Indian reservoirs. Stocking of silver carp was abandoned after the
experimental stocking in the Kulghari reservoir in Madhya Pradesh and the Getalsud
reservoir in Bihar. Common carp, however, is stocked regularly in many Indian reservoirs.

Table 9.4

Introduction of
exotic species in seven countries

Species

Zimbabwe

India

Thailand

Sri Lanka

Brazil

Cuba

Mexico

Oreochromis mossambicus

I**

x

x

x

x

x

x

O. mossabicus (red)

x

O. niloticus

x*

x

x

x

x

x

O. hornarum

x

x

x

x

O. aureus

x

x

x

Tilapia rendalli

I

x

x

x

x

x

T. zilli

x

x

Arapaima gigas

x

Macropterus salmoides

x

x

x

x

x

x

Cyprinus carpio

x

x

x

x

x

x

Ctenopharyngodon idellus

x

x

x

x

x

Aristhichthys nobilis

x

x

x

x

x

Hypophthalmichthys
molitrix

x

x

x

x

x

Limnothrissa moidon

x

Onchorhyncus mykiss

x

x

x

x

Salmo trutta

x

x

x

x

x

Clarias gariepinus

I**

x*

x

x

x

Catla catla

x

I**

x

x

Cirrhinus mrigala

I**

x

x

Labeo rohita

I**

x

x

Ictiobus cyprinellus

x

I. niger

x

Colossoma biddens

x

C. macropomum

x

Piaractus brachypomum

x

Lates niloticus

x

Cichlasoma managuensis

x

Mylopharygodon pisceus

x

Ictalurus punctatus

x

Carassius carassius

x

Osphronemus gourami

x

Trichogaster pectoralis

x

Helostoma temmincki

x

Puntius gonionotus

x

Lepomis macrochirus

x

Arapima gigas

x

Oryzias latipes

x

*Unauthorized introductions

**Indigenous

There are some incongruities in the policies of treating intensive aquaculture with
caution. A degree of overlapping makes it very difficult to distinguish between the two
systems. For example, in the Parana, Sao Paulo and Santa Catarina States of Brazil,
intensive aquaculture is practised by introducing a number of exotic species in ponds
created by impounding small streams. Since many of the streams are connected with the
tributaries of rivers, treating them as confined waters is not rational. Moreover, there
is always the chance of accidental introduction as happened in the Gobindsagar reservoir
of India. Following the accidental entry of 47 specimens of silver carp into the reservoir
in 1971, the fish have proliferated in amazing proportions almost eliminating the catla
populations. Sri Lanka and Cuba do not make any distinction between the extensive and
intensive aquaculture vis-à-vis species and stock them in their reservoirs at
will. These two island countries have practically no indigenous species that can
contribute to a sound reservoir fishery or support its intensive aquaculture. This
realization has led to the national policy of using exotic species in both culture
systems. Zimbabwe does not encourage the use of exotic fish in either of the systems.

The diversity of native ichthyofauna has been a major determining factor in guiding the
national policies on introduction of exotic species. Brazilian rivers have a rich species
spectrum which include apaiari (Astronotus ocelatus), cacunda (Plagioscion
surinamensis), pirarucu (Arapaima gigas), piratininga (Colossoma
brachypomum), tambaqui (Colossoma macropomum), tacunare comun (Cichla
ocellaris), and tacunare pinima (Cichla temensis) of the Amazons, curimata
pacu (Prochilodus argenteus) and piau verddero (Leporinus elongatus) of
the Sao Francisco, and a number of species from the northeast, which are considered to be
excellent for cultivation. Similarly, the availability of indigenous species such as
catla, rohu and mrigal is a major factor that shapes the Indian national policy on
exotics. National perceptions on introduction can be divergent, depending on the economic,
environmental and ethic considerations.

A major consideration affecting the national policies on exotics is the conservation of
the countries' faunistic diversity. This is well reflected in the federal guidelines
issued by IBAMA to the power generation, irrigation promotion and other agencies in Brazil
regarding fish species management. These concession agencies, which alter the riverine
ecosystem by erecting barricades, are duty-bound to stock the upstream stretches with
fingerlings of native species. Alternatively, they are responsible for providing fish
passes, ladders or any such hydraulic structures to facilitate upstream movements of fish.
Interestingly, interbasin translocation of fish within the country is not allowed. Thus,
tambaqui or pacu of the Amazon cannot normally be stocked in a reservoir on Parana.

The policy seems to be based on the premise that the depletion of certain fish occurs
above the dam site only because of the failure of fish movement, either at the adult or
juvenile stage. In reality, however, the loss of species occurs through more complex and
indirect processes. Often, the transformation of a riverine habitat into a lacustrine one
introduces a series of changes in water quality and to the plankton and benthic
communities. This pushes the less tolerant fish species toward the higher lotic sectors of
the reservoir, and when the whole river stretch is covered by a series of reservoirs,
lotic sectors disappear completely and the fish is endangered. Many power generation
companies have been breeding the indigenous fish species and stocking them in the
reservoirs without achieving any tangible benefit.

IBAMA regulations are mainly directed at the public sector companies that construct
hydroelectric and irrigation projects. The innumerable small impoundments, a substantial
percentage of which belong to the private sector, are created on small streams and
micro-catchments, and are either not under the purview of IBAMA regulations or no attempt
is made to enforce them. These small impoundments are used for extensive and intensive
aquaculture by stocking all types of exotic species such as Chinese carp, common carp,
African catfish, and a number of tilapia species, aside from the cultured Amazon species.
Considering that most of these small impoundments have indirect connections with the river
systems, the purpose of regulations followed in the large dams of the mainstream is
defeated. Moreover, the loss of production because of a lack of suitable species in large
dams cannot be ignored.

India, which is equally concerned about native species, has regulations concerning the
introduction of species. Unlike Brazil, the transbasin transfer of species within the
geographic boundaries of the country is not considered an introduction and there are no
restrictions on this. Thus, catla is not regarded as exotic to the Cauvery or other
peninsular rivers despite the fact that peninsular rivers have habitats which are
distinctly different from those of the Ganga and the Brahmaputra. The small west-flowing
drainages of the Western Ghats, the two large west-flowing drainages, Narmada and Tapti,
and a number of east-flowing rivers of peninsular India have ichthyofauna different from
the Ganga and Brahmaputra. Catla, rohu, and mrigal have been stocked in the peninsular
reservoirs for many decades now with varying results. In some of the south Indian
reservoirs they have established breeding populations. The main characteristic of the
Indian stocking policy is the heavy dependence on Indian major carp.

There is evidence that the Gangetic major carp have affected the species diversity of
peninsular cyprinids. The Indian policy on stocking reservoirs, though not very explicit,
does not allows the introduction of exotic species into the reservoirs. Paradoxically,
however, the government fisheries departments introduced the tilapia (O. mossambicus)
in a number of reservoirs in Tamil Nadu and Kerala during the 1950s and 1960s. Common carp
is being stocked by the government in many reservoirs with varying results.

The main exotic species (other than ornamental, recreational, and larvicidal fish),
i.e. tilapia, common carp, silver carp and grass carp, were originally brought to India
from the 1930s to the 1950s with the main objective of widening the species spectrum of
culture systems. During the 1960s, tilapia and common carp were stocked in the reservoirs
when there was little awareness of the possible impact of the introductions on the native
species. Further, the technological breakthrough in the large-scale seed production of
catla, rohu and mrigal took place only in the 1970s. The stocking of silver carp and grass
carp is not normally encouraged in Indian reservoirs, though a few isolated cases in
reservoirs of Tamil Nadu and the northeast are known. The three exotic species, bighead
carp (Aristichthys nobilis), Nile tilapia (O. niloticus) and African
catfish (Clarias gariepinus), brought in clandestinely by the fish farmers, have
not gained entry in to the reservoir ecosystems so far and they remain restricted to the
culture systems.

In their present form, legislative measures to protect the indigenous species and their
level of enforcement are not effective instruments for the following reasons:

O. mossambicus

and common carp have already been introduced and they are breeding
in many reservoirs.

There is no control over the use of exotic fish in culture systems.

Most of the farms where exotic fish are bred and reared are adjacent to natural water
bodies and there are no effective measures or guidelines for preventing accidental entry
of exotic fish into natural waters.

There is no provision for checking the illegal stocking of exotics, as the three species
were clandestinely introduced into culture systems.

Thailand has a similar situation where the national policy, which is not very explicit,
is only vaguely concerned with the protection of indigenous fish and the need for care
against the hazards of introductions. In effect, there are no specific guidelines, nor is
any serious effort made to enforce regulations where they do exist. Furthermore, the
government agencies stock the reservoirs with exotic fish, and there is practically no
check on the culture systems.

Sri Lanka and Cuba have very few inhibitions regarding the introduction of exotic
species. In the first place, the indigenous fish fauna found in both of these countries is
not rich enough to support good fisheries and to provide suitable candidates for the
intensive culture systems. In Cuba, the national priority to improve fish production from
small reservoirs overrides the need to protect the species diversity.

The situation in Mexico is similar to that in Brazil with the difference being that
SEMARNAP, which has an important role in the framing of regulations, is actively involved
in the fishery management activities. The role of IBAMA in Brazil is to give guidelines to
a number of agencies that manage fisheries in reservoirs. There has been a sharp decline
in the percentage of native species in the natural lakes of Mexico with a corresponding
rise in the percentage of exotic ones. The effectiveness of national policies in different
countries and their level of enforcement can be summarized as follows.

Zimbabwe

: Very clear national policy against introductions - enforced at a
reasonably good level.

: National policy not well defined  in effect no check on
introductions.

Cuba, Sri Lanka

: Liberal national policies on introductions.

Tilapia and its role in yield improvement

Tilapia is the most widely introduced fish in the world. Oreochromis mossambicus
and O. niloticus are very popular in Asia while, O. aureus, and T.
rendalli are also common in Latin America. Three species of tilapia, O.
mossambicus, O. niloticus and T. rendalli, have played a clear role in the
striking increase in fish production achieved by Sri Lanka. Surprisingly, tilapia, which
was introduced in India during the same year as it was in Sri Lanka, did not produce
equally good results. Even after extensive stocking in almost all reservoirs in Tamil Nadu
and Kerala, the yield rate in the two states remained much lower than that of Sri Lanka
which has a similar geoclimatic regime. The absence of large predators and less
competition from weed fish could be the reasons for the better performance of tilapia in
Sri Lanka. The introduction of tilapia has proved to be equally successful in Cuba.

Impact of species enhancement

The introduction of species has been used as an effective instrument to improve fish
yields in the reservoirs of Sri Lanka and Cuba. These two countries have achieved dramatic
increases in fish production. In Sri Lanka, at one stage, the tilapia-based fisheries of
reservoirs accounted for 20% of the national fish production, amounting to 27000-38000
t/yr which was equivalent to 300kg/ha/yr. Later on the yield declined owing to the
withdrawal of official support following a policy reversal on inland fisheries. Similar
interventions in species spectrum have resulted in striking increases in production in
Cuba. In northeastern Brazil, the DNOCS Project areas show higher rates of production
compared to the south and southeast.

The policy on introductions is directly related to fish yields in the seven countries.
Brazil and India, which do not favour introductions, get less yield from their reservoirs.
In Brazil, there is a sharp difference in yield rates between the northeastern reservoirs
stocked with exotic and transplanted fish and the southern and southeastern ones where
only native species are stocked. A study of production trends for five years from 1987 to
1991 clearly indicates that the sharp decline in fish production observed during the
period was attributable to the fall in fish introductions.

Environmental enhancement

Improvement of the nutritive quality of water by the selective input of fertilizers is
a very common management option adopted in intensive aquaculture. However, similar
interventions in larger water bodies to augment the biomass have limited scope mainly
because they interfere with other water uses. In any case, this option requires careful
consideration in terms of its possible impact on the environment. It is generally believed
that most of the lakes and reservoirs may have sufficient nutrient inputs and any
excessive nutrient loading can lead to serious pollution problems. However, scientific
knowledge to guide the safe application of this type of enhancement and the methods used
to reverse environmental degradation are still inadequate. For these reasons, the
selective input of fertilizers is not a very common management tool in the countries
studied. China is known to have made great use of this option to augment production from
small reservoirs. Cuba, following China's example, has tried fertilizing micropresas
using both organic and inorganic fertilizers. This is also practised selectively in the
community water bodies of Thailand.

9.2.4 National priorities

The contribution of small water bodies to national inland fish production shows extreme
variations because of the differences in the availability of water bodies and suitable
fish species, modes of management, legislative measures and institutional support
regarding research and development, infrastructure, and marketing. Existing social
structure and traditional food preferences also play a key role in the level of
exploitation of this resource. The inhabitants of Latin American countries consume more
red meat than fish. Consequently, inland fisheries development received less attention. In
Brazil, the protection of species diversity in the rivers takes precedence over fisheries
considerations. However, Cuba, an exception in Latin America, made immense progress in
developing small reservoir fisheries. Asian countries, especially India, give high
priority to fish production from inland water bodies and reservoirs in particular in order
to improve the availability of food for its people. The Village Fish Ponds Project of
Thailand receives high priority. State support for inland fishery programmes was withdrawn
in Sri Lanka owing to pressure from religious groups. This adversely affected the pace of
development after 1990.

The most common point of conflict faced by fishery development in the countries studied
is with the environmental agencies. Stocking of water bodies with exotic and indigenous
fish species, the quantity, size and life stages of fish caught, and many similar factors
raise a number of environmental issues. Many governments have attempted to integrate the
norms of conservation of natural resources into the fish yield improvement programmes.
IBAMA of Brazil and SEMARNAP of Mexico are making such attempts. The Department of
National Parks and Wildlife Management (DNPWLM) of Zimbabwe works in conjunction with
AGRITEX to achieve such goals. In India, however, there is very little coordination
between the Ministry of Environment, the fisheries departments of the states, and the
Ministry of Agriculture. Sri Lanka, Cuba and Thailand have very little organizational
backup in such matters.

Organizational and infrastructure support

The degree of national interest in a sector can be easily gauged by the level of
organizational and infrastructure support it receives. Despite wide recognition of the
importance of inland fisheries in general, and small water bodies in particular, many
countries have not developed an adequate organizational framework to harness this
resource. In most of the countries the fisheries departments and ministries deal with
licensing and the enforcement of regulations. In Brazil, Mexico and Zimbabwe steps have
been taken to streamline procedures by including these functions in the operations of
national agencies such as IBAMA, SEMARNAP and AGRITEX/DNPWM in order to make them more
responsive and effective. Table 9.5 illustrates the levels of governmental involvement in
different countries.

Table 9.5

Levels of governmental involvement in
inland fisheries

Country

National

Provincial

Regional

Others

Zimbabwe

AGRITEX

-

-

Community

India

Ministry of Agriculture

State governments

-

Local self governments/fisheries development corporations

Thailand

Fisheries Department

-

VFP Project

-

Sri Lanka

Fisheries Department

-

-

-

Brazil

IBAMA

DNOCS

Power/irrigation companies

Cuba

Aquaculture Enterprise

-

-

-

Mexico

SEMARNAP

State governments

-

-

The roles and modus operandi of IBAMA, SEMARNAP and AGRITEX/DNPWM are
different (Table 9.6). While IBAMA issues guidelines and shapes legislation on matters
regarding fisheries management, it has a limited role in actual management, except for the
sponsorization of some regional projects like CEPTA, DNOCS, PAPEC, etc. A vast majority of
small and large water bodies are managed by other agencies and there is very little
interaction between them and IBAMA. Furthermore, fisheries receives low priority among the
many activities IBAMA is involved with. There is no scope for day-to-day verification of
enforcement of federal guidelines and, in any case, IBAMA does not have the resources to
do so. In contrast, SEMARNAP has the multiple role of legislating, setting guidelines, and
actually managing the fisheries of at least some of the water bodies. Moreover, Secretaria
de Pesca which has merged with SEMARNAP had a well-organized national network and formed a
strong component of the organization both at the national and state levels. The procedures
followed by SEMARNAP and AGRITEX/DNPWM in issuing fishing licences are rather lengthy.

Table 9.6

Functions of various governmental
agencies in the fishery management process

Policy guidelines

Actual management

Zimbabwe

AGRITEX

Community, individuals

India

Ministry of Agriculture

State governments, fisheries, district and village level
bodies, corporations, cooperative societies

Thailand

Ministry of Fisheries

Ministry of Fisheries

Sri Lanka

Ministry of Fisheries

Ministry of Fisheries

Brazil

IBAMA

Power and irrigation companies, private farmers

Cuba

Aquaculture Enterprise

Aquaculture Enterprise

Mexico

SEMARNAP

SEMARNAP, state governments, communities

One of the beneficial effects of such organizations has been the creation of
infrastructure. The national Aquaculture Enterprise of Cuba and SEMARNAP of Mexico have
created a chain of aquaculture centres throughout the respective countries to produce fish
seed for stocking reservoirs and to organize fishing groups. India does not have any
specialized national organization comparable to IBAMA and SEMARNAP, mainly because
fisheries is a state matter under the Indian Constitution. However, the central government
has been instrumental in developing inland aquaculture in the country through the highly
successful Fish Farmers' Development Agency (FFDA). By providing financial assistance and
technological expertise to the fish farmers through the state governments, this project
has brought 0.4 million ha under the fold of aquaculture and increased the productivity
level to 2100 kg/ha.

Federal and state jurisdictions

The three large countries, Brazil, India and Mexico have a federal structure where the
states have their own legislative machinery. In India, the state is divided into
districts, taluks and villages (municipalities or corporations in towns and
cities). Fisheries is a state subject and the fishing management of the reservoir falls
within the jurisdiction of state governments. Some states redelegate their rights to lower
levels such as district, taluk and village administration. Each state has its own
fisheries department and sets of fishery laws. In Mexico, aside from the federal fishery
laws, many states have their own fisheries departments and fishery laws. In Brazil, the
public sector companies are managing fisheries in the large reservoirs following the IBAMA
guidelines. The smaller countries have more centralized fisheries administration.

The management norms followed in a country are affected by the prevailing
socio-economic milieu. For example, the Cuban system of state-controlled management is
derived from the Chinese experience and has very few parallels to the democratic world.
High population and acute rural unemployment necessitate a policy which allows maximum
employment opportunities. Moreover, the Indian Constitution allows a number of concessions
to the socially and economically weaker sections of society which often prevents the
enforcement of restrictions on fishing effort. In the State of Andhra Pradesh licences are
issued free of cost which not only results in virtually free fishing leading to depletion
of stock but also makes the collection of vital statistics very difficult.

A common problem faced by all the countries is the difficulty of enforcing the fishery
laws. Patrolling all the open waters to check unauthorized fishing and to enforce mesh
regulations is not feasible owing to the enormous cost involved. Resources at the disposal
of the governments and the agencies managing the fisheries are a constraint in effective
implementation of the restrictions.

A high level of motivation among the fishers is the only remedy but this is retarded by
poverty, ignorance and lack of awareness. The recent efforts made in Zimbabwe and Brazil
to institutionalize community management by introducing the concept of equity and
democratic functioning in the rural areas are worth encouraging.

9.3 Comparison of management practices

The fisheries management of small water bodies, especially the small reservoirs, can be
summarized as stock management, species management, fishing effort management, and
organizational/infrastructural support. The emphasis on management varies in countries
depending on the national priorities, availability of facilities and the technological
level (Table9.7).

Table 9.7

Relative efficiency of various
managements in different countries

Country

Stock management

Species management

Fishing effort management

Management of organizational/
infrastructural support

Zimbabwe

x

-

x

x

India

xx

x

xx

x

Thailand

x

xx

x

x

Sri Lanka

x

xxx

x

x

Brazil

xxx

x

xx

xxx

Cuba

xxx

xxx

xx

xxx

Mexico

xx

xx

xx

xxx

Key: x - poor; xx - moderate; xxx - satisfactory

A common feature of reservoir fisheries all over the world is their basic common
property character, which is also the cause of all the dilemmas faced by the reservoir
fishery managers. Fishery regulations in reservoirs are as essential as they are difficult
to enforce. The cost involved in policing the regulations exceeds the monetary value of
the resource itself, so that many governments find it difficult to allocate money for this
purpose. At the same time the real value of the resources is much more important than
their monetary value. Environmental, cultural, moral and aesthetic considerations prevent
a purely materialistic view being taken on the subject. The emerging trend of a modern
community management concept is worth trying. Africa and Latin America have already taken
a lead and it must be tried in Asia as well where there is a tradition of community
management of reservoirs. The cases in point are the Mwanje experiment in Zimbabwe and the
Coxitore community in Brazil.